Late 1920s Eveready Model 1 TRF Set need info

[vortalexfan]

Hello everyone, today I found on Facebook Marketplace locally a late 1920s Eveready Model 1 TRF Neutrodyne Radio with its original matching speaker attachment for $75 and according to the owner he says it needs to be rewired and the speaker's cone is torn (to what extent it is torn I am unsure, but more than likely it should be easily repaired by just using brown coffee filter paper and diluted Elmer's Glue).

My question is, how fair is the asking price (I haven't gotten it yet as I just messaged the seller about 45 minutes ago and I more than likely won't hear from him until tomorrow) and if its not a fair asking price what should I offer him price wise?

Also how hard are these early TRF Neutrodyne Sets to repair? I'm asking as this would be my first TRF Set I've ever repaired.

Any help or advice in this matter would be appreciated.

Thanks.

P. S. I do have the pictures of the unit in question from the Facebook Marketplace posting.

[Electronic M]

That isn't a bad price given cabinet condition assuming all the tubes are correct types and most aren't bad.

TRF sets vary from a walk in the park to an endless hunt for unobtainium. If all that's bad is a tube or two, some caps and maybe a fixed resistor or 5 TRFs are simple and easy....but if a transformer is bad on a 20s set it can be very difficult to impossible to find one and if you don't have the engineering skills (or are stuck on exact replacement for originality) to figure out a non-correct but functional replacement your going to be stuck with a paper weight. Some sets have goofy problems like potmetal chassis that crack and shatter and are irrepairable (I had a radiola 44/46 like that).

On the rare occasion I accept a set like that for repair I tell the owner "I'm going to try to verify the continuity of the coils and make sure it's repairable before I work on it. If its missing something I can't get I'm returning it as is and not fixing it. If I don't find anything wrong but can't fix it I'm going to waive my labor charge collect the cost of the installed parts, and return it to you as is". If they know there is no guarantee it is repairable going in that generally prevents troublesome levels of dissapointment on occasional unfixable patients.

[vortalexfan]

Originally Posted by Electronic M

That isn't a bad price given cabinet condition assuming all the tubes are correct types and most aren't bad.

TRF sets vary from a walk in the park to an endless hunt for unobtainium. If all that's bad is a tube or two, some caps and maybe a fixed resistor or 5 TRFs are simple and easy....but if a transformer is bad on a 20s set it can be very difficult to impossible to find one and if you don't have the engineering skills (or are stuck on exact replacement for originality) to figure out a non-correct but functional replacement your going to be stuck with a paper weight. Some sets have goofy problems like potmetal chassis that crack and shatter and are irrepairable (I had a radiola 44/46 like that).

On the rare occasion I accept a set like that for repair I tell the owner "I'm going to try to verify the continuity of the coils and make sure it's repairable before I work on it. If its missing something I can't get I'm returning it as is and not fixing it. If I don't find anything wrong but can't fix it I'm going to waive my labor charge collect the cost of the installed parts, and return it to you as is". If they know there is no guarantee it is repairable going in that generally prevents troublesome levels of dissapointment on occasional unfixable patients.

Ok, thanks for the info, from what I can see in the pictures, the tubes look like they're all there and accounted for, the cabinet looks pristine and so does the speaker cabinet. I'll let you know what I find out if I end up getting it. I do have some of the tubes that this radio uses in my tube stash already, including several known good 80 rectifier tubes and a NOS RCA 26 tube.

I've seen several YouTube videos posted by someone with the username Glasslinger who does nothing but restore old TRF sets from the 1920s and it seems like all he ever has to do to them is just clean them and maybe replace the fixed resistor (the one that fits into a socket similar to a fuse socket) and maybe change out a tube or two, other than that they seem to come to life with very little work done to them (grant it the ones he works on are battery units rather than AC units like this one is).

Anyways thanks for the feedback.

[vortalexfan]

Ok, I got the radio, and the cabinet in in really nice shape, but the wiring is atrocious inside, it has dry rotted rubber wiring inside and the original power cord was cut at some point in time. It has it has its grid leak resistors intact, the 2 megohm and a smaller one of unknown value as the part of the original label that said the value of the resistor was missing.

It has its original speaker intact which had its original grille cloth replaced at some point in time and the speaker cone is torn in several spots including a spot where there's a small section of the cone missing (see pictures below).

It also has all of the correct tubes in the unit, which are all RCA or RCA Cunningham branded tubes.

I hope this unit will be fairly easy to bring back to life.

I found the Rider's manual for this radio but its kind of hard to decipher what's what in it because it doesn't give values for the capacitors or resistors just part numbers which doesn't even have a crossreference chart on the manual to tell you which part is which.

[vortalexfan]

It looks like its mainly a bunch of bad rubber wire, and there's a couple of transformers that are just hainging loose inside the chassis, one of them is the output transformer and the other one I'm not sure what it is and a third transformer on the tuner section of the chassis which is also kind of just hanging loose on the tuner chassis.

See picture below.

[Electronic M]

Rubber wiring sucks. If I know a set has it I tend to think twice about getting it as rewiring an entire radio is a pain...it's uncommon for a large amount of rubber wiring to be used in a 20s set.

If riders isn't helpful look for a Beitmans covering 20s sets. They were a competitor to riders and one of the only second sources of literature for sets that old.

Some 20s sets the wax paper caps used as coupling, bypass and as B+ filters (lytics weren't used much back then) go bad and others they are fine...I don't know that brand well enough to say which it's likely to be. If you have a good leakage current tester you should check the original caps.

[vortalexfan]

Originally Posted by Electronic M

Rubber wiring sucks. If I know a set has it I tend to think twice about getting it as rewiring an entire radio is a pain...it's uncommon for a large amount of rubber wiring to be used in a 20s set.

If riders isn't helpful look for a Beitmans covering 20s sets. They were a competitor to riders and one of the only second sources of literature for sets that old.

Some 20s sets the wax paper caps used as coupling, bypass and as B+ filters (lytics weren't used much back then) go bad and others they are fine...I don't know that brand well enough to say which it's likely to be. If you have a good leakage current tester you should check the original caps.

Well the problem is I didn't think this thing was going to be full of rubber wiring, I just thought maybe it was going to be old crumbly cloth wiring which would of been a little bit easier to replace than old rubber wire.

The strange thing about the rubber wire in this set is that it looks almost like the rubber wiring in this set just melted at some point in time from being stored in a hot location like an attic and then the rubber hardened afterwards which caused the wires rubber insulation to "weld" together.

Also the rubber grommets did the same thing, they melted and then hardened up and the rubber insulation from the wires that were going through those grommets became part of the grommets.

As for the capacitors the only capacitors I see in this unit are 3 block capacitors that are mounted to the underside of the tuner chassis 2 of them of which are 2 section caps that have one section soldered to the metal housing of the can and the third one is utilizing both sections.

as for the grid leak resistors, there are 2 of them total, one is a 2 Meg unit that measures around 2.8 Meg, and the other one is an unknown value as the paper label that told the value of the resistor is partially missing, and when I tried to get a reading from that resistor I couldn't get a solid reading from it, it measured anywhere from 500k to 22 Meg but it wouldn't settle on a specific value.

When I looked up this radio online it said this was a Neutrodyne TRF Set, but when I looked at the chassis closer it appears to have IF transformers with trimmer condensers on the top of the chassis which I didn't think that TRF Sets used IF cans or Adjustment trimmers, the way this set is set up it reminds me more of an early Superheterodyne set.

Also what's the purpose of the rotating coil that's attached to the left knob?

[Electronic M]

Most TRF sets have a an antenna transformer and a coupling/tuning transformer between each TRF RF amp stage. Some sets leave the transformers out in the open turning each one 90 degrees to prevent coupling, some sets put the transformer tube and tuning cap of each stage in its own dedicated stage shield, others individually shield the can so it looks like an IF can.
Your set looks to be a single knob TRF those require a trimmer on each coupling transformer to adjust the set so each stage is peaked at the same freq and track properly with each other.

A transformer with one winding connected to a knob and one winding fixed is a variable coupling transformer...it's probably in the antenna circuit and probably acts as a RF attenuator (which was usually effectively the volume control in a TRF).

[dieseljeep]

Originally Posted by Electronic M

Rubber wiring sucks. If I know a set has it I tend to think twice about getting it as rewiring an entire radio is a pain...it's uncommon for a large amount of rubber wiring to be used in a 20s set.

If riders isn't helpful look for a Beitmans covering 20s sets. They were a competitor to riders and one of the only second sources of literature for sets that old.

Some 20s sets the wax paper caps used as coupling, bypass and as B+ filters (lytics weren't used much back then) go bad and others they are fine...I don't know that brand well enough to say which it's likely to be. If you have a good leakage current tester you should check the original caps.

Look under Riders National Carbon model 20. It's on the same page showing models 1,2,3.
Dave

[vortalexfan]

Originally Posted by dieseljeep

Look under Riders National Carbon model 20. It's on the same page showing models 1,2,3.
Dave

I looked there. Didn't have much luck with it. It seems to be incomplete.

[Kevin Kuehn]

Originally Posted by vortalexfan

I looked there. Didn't have much luck with it. It seems to be incomplete.

Take a look at American Bosch model 28. I'm pretty sure Bosch made those for Eveready. http://www.nostalgiaair.org/Resources/767/M0040767.htm

[vortalexfan]

Originally Posted by Kevin Kuehn

Take a look at American Bosch model 28. I'm pretty sure Bosch made those for Eveready. http://www.nostalgiaair.org/Resources/767/M0040767.htm

Yep, took a look at that and it sure was the same unit, the Eveready version of the service information was missing quite a bit of helpful information including the parts listing and the information about the transformer and the "filter can" assembly and how to service them, and the rest of the resistors and capacitors and their values.

So as far as the Filter Can assembly goes, since it was meant to be removed and replaced as a whole assembly I'm assuming that in order to replace the old filter capacitors I would need to just cut out the old filter caps and just solder new capacitors onto where the old capacitors that were in the filter can soldered to?

Also I'm going to assume the original Filter Choke is more than likely fine yet so it should be fine to leave that in circuit am I correct?

As for the old filter capacitors go, I'm assuming I should just go with 450V Caps to be on the safe side since they didn't specify a voltage in the service information?

Also I see the 3 Meg Grid Leak Resistor in the parts list, but I don't see the second fuse looking resistor that was on top of the chassis listed in the parts list, unless I'm missing something...

Thanks for your help.

Edit: I figured out what that second fuse style resistor is on the top of the radio chassis, its the 50,000 Ohm (50k Ohm) Plate Resistor which measures open and I searched eBay and couldn't find anything.
I know of someone who might have the part (its an older gentleman who goes by Glasslinger on YouTube, who works on these old 1920s vintage TRF sets all the time) but I'm not sure how to go about contacting him and or if he would even be willing to send me one of his resistors if he had one.

[Kevin Kuehn]

How about leave the defective 50k above chassis for originality, snip the wiring below and add a modern replacement under chassis? It's no more sacrilegious than changing caps. The filter choke, who knows, you'll find out if it's good once you trace the wiring or fire the set up under load. These things are so old that the copper wire used had impurities along with not so good insulating varnish which allows the wire to oxidize and corrode open over time. Same issues with the stage coupling transformers. The finer wire winding's are most subject to corroding open.

[vortalexfan]

Originally Posted by Kevin Kuehn

How about leave the defective 50k above chassis for originality, snip the wiring below and add a modern replacement under chassis? It's no more sacrilegious than changing caps. The filter choke, who knows, you'll find out if it's good once you trace the wiring or fire the set up under load. These things are so old that the copper wire used had impurities along with not so good insulating varnish which allows the wire to oxidize and corrode open over time. Same issues with the stage coupling transformers. The finer wire winding's are most subject to corroding open.

Ok, thanks! I might just do that. What wattage should I use for that plate resistor? They didn't specify a wattage in the service manual.

Also if the filter choke is bad, could I just replace that with a resistor?

Thanks.

[Kevin Kuehn]

Originally Posted by vortalexfan

Ok, thanks! I might just do that. What wattage should I use for that plate resistor? They didn't specify a wattage in the service manual.

Also if the filter choke is bad, could I just replace that with a resistor?

Thanks.

Half watt should be more than enough. You could use a resistor but you won't get as much filtering with the stock value capacitors.

Here's an interesting post from over on ARF.

https://antiqueradios.com/forums/vie...hp?f=6&t=72312

Towards the end is an explanation of how to neutralize the set(as in Neutradyne). Good to know since the manufacture didn't include it in the Riders service literature. Actually they probably did include that process in a more complete service manual available to their dealers.